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  Subjects -> WATER RESOURCES (Total: 160 journals)
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Journal of Water Chemistry and Technology
Number of Followers: 8  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1934-936X - ISSN (Online) 1063-455X
Published by Springer-Verlag Homepage  [2469 journals]
  • Direct Sunlight Driven In2S3 Thin Film Based Water Treatment Proto-Type

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      Abstract: A multi-faceted energy intensive technology that can be used for water disinfection and synthesis of electrolysed water (EW) is the need of the hour to achieve a sustainable post COVID 19 water management strategy. Direct sunlight driven processes are legislatively green technologies and hold the key in environmental sustenance. The development of a laboratory proto type reactor powered by a photovoltaic module for the treatment open source river water is described in this paper. This paper reports on the efficacy of the developed proto type technology for multipurpose application namely: (1) the production of Electrolysed water (EW) in a cost efficient manner using direct sunlight and (2) the removal of organic impurity from water using direct sunlight without the use of any photo catalyst or membrane. The prototype reactor utilizes chemical spray pyrolysis deposited highly photo-conducting indium sulphide thin films grown on fluorine doped tin oxide (F:SnO2) substrate (coated using chemical spray pyrolysis technique in-house) as the photo electrode. Dissolved organic matter arising in river water has distinctive fluorescence properties, and this research has utilized it to identify dissolved organic substances in both random samples and treated water. The work proves that photovoltaic module powered electrolytic reactors consisting of In2S3 electrodes can be used for treatment of river water. A diaphragm free, energy intensive route for the production of electrolysed water with the use of non-hazardous NaCl as the electrolyte has been demonstrated here. We conclude that In2S3 electrodes can be used for non-photo catalytic reduction of humic-derived impurities in river water. These results are also encouraging on the prospects of treating Nitrates present in the river water. The likes of techniques as described in this report that do not use photo catalyst or membranes may pave way for real time photovoltaic module powered floating reactors that can decontaminate water bodies on a large scale. The technique used by us demonstrates that a chlorine free route can be optimized for the synthesis of EW eliminating the production of large amounts of wastewater with high levels of biological oxygen demand (BOD).
      PubDate: 2022-04-01
       
  • Chemical Modification of Polyamide Thin-Film Composite Membrane by Surface
           Grafting of a Vinyl-Based Monomer

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      Abstract: Currently, the use of membrane techniques has undergone dynamic growth, particularly due to the diversification of their fields of application. This trend is expected to increase owing to new environmental protection requirements and thanks to the increasingly competitive energy and technical-economic performances offered by membrane processes. New research is constantly being carried out to better understand the functioning of membranes, to create more efficient or more specific membranes, and also to develop processes for new applications. The aim of this work is to improve the performance of a polyamide reverse osmosis membrane by chemical modification of its surface. Thin film polyamide reverse osmosis membranes are widely used for desalination. However, these membranes face a fouling issue that results in low permeation flux, which is undesirable in the reverse osmosis process. An interesting alternative to improve the properties of these polyamide composite membranes is the use of chemical surface modification. In this context, we studied the chemical grafting of vinyl acetate monomer on the surface of a polyamide membrane in order to improve the selectivity towards sodium ion. The chemical grafting was carried out by radical polymerization of vinyl acetate monomer in the presence of benzoil peroxide as an initiator in an organic medium. Unmodified, modified membranes and evolution of the polymerization reaction were analyzed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), interferometric electron microscopy, and contact angle. An application with a front filtration module was investigated to confirm the improved selectivity for sea water. This study revealed an improved efficiency of the reverse osmosis PA membrane after the grafting of polyacetate monomer on the active layer of this membrane.
      PubDate: 2022-04-01
       
  • Screening of Composite Flocculants for Food Wastewater Treatment

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      Abstract: Food wastewater contains abundant nutrition substances causing high biological load on the environment. Inorganic and organic synthetic high-polymer flocculants have been most commonly used because of their flocculating efficiency and low cost. Natural organic flocculants possess a certain synthetic advantage. To investigate the optimal flocculant for food wastewater treatment, effects of five organic and chemical flocculants, being Chitosan (CTS), Polyaluminum sulfate (PAS), Polyaluminium chloride (PAC), Polyaluminum ferric silicate (PSAF), Polyacrylamide (PAM) and their pair composite flocculants by stirring have been studied. Under the condition of 300 rpm for 30 min by magnetic stirring apparatus, the optimal dosages of PSAF, CTS, PAC, PAM and PAS were 3.30, 2.19, 5.69, 6.56, and 3.30%, respectively. Therefore, effect of CTS was optimal because of its 87.24% maximal absorbance reduction. CTS demonstrates biodegradability and antibacterial activity, and the hydrophilicity introduced by the addition of polar groups is able to develop secondary interactions (–OH and –NH2 groups involved in H bonds with other polymers), which results in its excellent flocculant property. The optimal proportions of two components in composite flocculant A (CTS-PSAF), B (PAC-PAM), C (P SAF-PAC), D (PAS-PAM), E (CTS-PAS), F (CTS-PAM) were respectively determined as 0.53, 0.87, 0.46, 0.40, 1.33, and 1.67. Correspondingly, the optimal stirring speeds of every composite flocculant were 20, 20, 125, 125, 160, and 20 rpm. Thus, composite flocculant A was optimal due to 42.89% maximal CODCr removal efficiency and 51.54% maximal BOD5 removal efficiency (CODCr—chemical oxygen demand determined by potassium dichromate method). The results have presented that CTS and its pair flocculants CTS-PSAF are effective for food wastewater treatment, indicating that CTS-based flocculants exhibit effective pollution removal ability with wide applications.
      PubDate: 2022-04-01
       
  • Assessment of Water Quality and Ecological Condition of the Oster River

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      Abstract: Significant, multilateral, and long-term use of Ukraine’s water resources in various spheres of human activity has led to the deterioration of the state of many water management facilities and the complication of their operational regime. An unfavorable ecological situation developed in 2016 around the Oster River flowing through the territory of the Chernihiv region. This was caused by many factors of anthropogenic impact (intentional and unintentional) that have formed in the agricultural, industrial, housing, and communal sectors. A combination of these factors resulted in some changes occurring in the river ecosystem. The main goal of the present work is an analytical study of water quality in terms of hydrochemical indicators and an assessment of the ecological state of waters of the Oster River. The chemical composition of the surface waters of the city of Oster was analyzed, in particular, by stripping voltammetry for the concentration of heavy metal ions Pb2+, Cu2+, Zn2+, and Cu2+ and colorimetry for the concentration of total Mn2+, \({\text{NH}}_{4}^{ + }\) , \({\text{NO}}_{3}^{ - }\) , and \({\text{PO}}_{4}^{{3 - }}\) . Insignificant excesses of the water quality standard were found for fishery reservoirs in the concentration of organic substances in terms of chemical and biological oxygen consumption, ammonium ions, and phosphate ions. Pollution with ions of these heavy metals in water samples was not recorded, but the concentrations of lead and copper ions tend to increase. Exceeding the total iron and manganese indicators is typical for the Polesye rivers. These phenomena may result from anthropogenic loads and natural anomalies. A comprehensive assessment of the quality of surface waters based on the calculation of the water pollution index revealed that in 2018–2020, surface waters of the Oster River belong to Class III and are characterized as “moderately polluted.” The study results are useful for areas of water protection activities to improve the state of the Oster River and eliminate the negative consequences of anthropogenic impact.
      PubDate: 2022-04-01
       
  • Dynamic Model of Water Quality Evolution

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      Abstract: Spatiotemporal variability in water quality is often expressed so clearly that the variance of the monitored parameters exceeds their average value. This circumstance substantially complicates water management. It is practically important and theoretically interesting to find any dynamic trends in the processes of natural water quality evolution. These trends are difficult to detect with a linear approach to the evolution of quality parameters that are random in nature, but it is possible to take into account the nonlinearity of natural aquatic systems. The nonlinear logistic rule derived in this way enables estimation of the composition of water as a function of the intensity of the processes of its pollution and self-purification. It is shown that an aquatic ecological system shows linear behavior only in the case of slow processes when its parameters approach certain stable (equilibrium) values. With an increase in the intensity of pollution and self-purification processes, cyclic fluctuations of the monitored parameter occur. Their amplitude remains small at a low rate of pollution and increases with an increase in the pollution rate or even is accompanied by bifurcations with a further transition to total chaos. This is an indication of the substantial nonlinearity of natural aquatic systems, which is manifested, in particular, as energy dissipation of ordered processes and as bifurcations, i.e., unexpected changes in controlled parameters. In this case, order parameter fluctuations that determine singular contributions to the controlled dynamic characteristics serve as influencing nonlinearity factors. The performed theoretical analysis is confirmed by the observational data, which show that the aquatic ecological system under study has a noticeable degree of organization. The water management efficiency can be improved by taking these circumstances into consideration.
      PubDate: 2022-04-01
       
  • Exploration of Potential Indigenous Fungal Species for Mycoremediation of
           Industrial Effluent

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      Abstract: Lack of environmental friendly treatment of industrial effluent is a severe global problem. Microbial treatment may serve as potential technique to overcome the problem of environmental friendly management of industrial effluents. The present research was undertaken to find out potential indigenous fungal isolates/species from relevant industrial wastewaters and to explore their efficacy in mycoremediation of industrial effluent. Fungal species were isolated from textile, washing, dyeing, tannery and composite wastewaters, and efficient isolates were selected through screening against biobleaching of the effluent. Subsequently the selected fungal isolates were evaluated in mycoremediation of industrial effluent. Eleven fungal isolates were identified as species of Trichoderma, Penicillium, and Aspergillus. Finally, two species (M206 (Aspergillus sp.) and B102 (Penicillium sp.)) were used for mycoremediation. Significant improvement of biobleaching/bioremediation of treated effluent was noticed. After 5 days of treatment maximum 94 and 93% of turbidity, 48.45 and 38.14% of total solids (TS), 96.67 and 95.56% of total suspended solids (TSS), 36.98 and 36.12% of total dissolved solids (TDS) removal were recorded in treated effluent with prior grown fungal species of M206 and B102, respectively compared to control. Moreover, 72.93% chemical oxygen demand (COD) removal was also monitored by both species. Conversely, 93% turbidity and 89% TSS removal were recorded in fresh fungal spores suspension of M206, which were closer to the values obtained at 3 days prior grown treatment. Majority of the studied parameters suggested that the fresh fungal spores suspension exhibited superior performance in mycoremediation of effluent. Definitely fresh fungal spores suspension of M206 played superior roles in mycoremediation of the treated industrial effluent. Mycoremediation by fresh fungal spores suspension might be opened as a potential technique of industrial effluents treatment.
      PubDate: 2022-04-01
       
  • Determination of 2-Methylisoborneol and Geosminin Water by Using Stir Bar
           Sorptive Extraction-Thermal Desorption Coupled with GC-MS

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      Abstract: In water system, odorous compounds are often associated with the metabolites of microorganisms as fungi and blue-green algae, and the related compounds have been commonly found in lakes and reservoirs. Among those compounds, geosmin (GSM) and 2-methylisoborneol (2-MIB) have been treated as main odor compounds, which cause the off-flavor issues in natural sources such as freshwater, water reservoirs, marine water ecosystems and even in drinking water. Since of the strong smell of GSM and 2-MIB with earthy flavor and odor, they can be simply detected by human nose. Although those compounds are harmless to human health at certain level, high accumulation in natural water and drinking water led to an undesirable odor. Thus, the detection of the presence of those off-flavor compounds is first step to address above problem. To analysis the undesirable odorous compounds in water and aquaculture products, a concise and sensitive method has been developed by using stir bar sorptive extraction-thermal desorption coupled with gas chromatography-mass spectrometry (SBSE-TD-GC-MS) in the study. SBSE-TD-GC-MS has been optimized and validated through analyzing 2-MIB and GSM in aquatic samples. The calibration curves of 2-MIB and GSM were linear in the range of 0.5–100 ng/L (r2 > 0.995, RSDs < 3.5%). The limit of detection (LOD, S/N = 3) and limit of quantification (LOQ, S/N = 10) of 2-MIB and GSM were both ~0.2 and 0.5 ng/L, respectively. The recoveries of 2-MIB and GSM were 86–113% with good precision (RSDs < 8%) by spike in 2.5 and 25 ng/L standard compounds. This method was successfully applied to monitor and determinate the amount of 2-MIB and GSM in four types of water samples. Thus, SBSE-TD-GC-MS, a developed technique with high sensitivity and good recoveries, can be applied to detect odorous compounds at very low concentration, by using significantly smaller amounts of water samples, without any pre-concentration.
      PubDate: 2022-04-01
       
  • Investigation of Amoxicillin and Ciprofloxacin Behaviours in Sequencing
           Batch Reactor and Their Effects on Chemical Oxygen Demand Removal
           Efficiencies

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      Abstract: In this study, the behaviors of amoxicillin and ciprofloxacin were investigated in the conventional treatment systems in both theoretical and experimental manner. The doses of these pharmaceuticals which inhibit the treatment were determined. The efficiencies of amoxicillin and ciprofloxacin in response to dose increments were determined by monitorization of chemical oxidation demand parameter. Based on the results of these studies, amoxicillin doses >35 mg/L and ciprofloxacin doses >10 mg/L reduced treatment efficiency by leading changes in the structure of activated sludge. The sludge became sticky and dark due to the increase in the extracellular polymeric substance formation in the bacteria with increasing pharmaceutical concentration. The highest and lowest removal efficiencies were found as 39.8 and 14.9% for amoxicillin doses of 5 and 20 mg/L, respectively. The greatest part of the removal efficiency was achieved through adsorption in the sludge (33.8%). On the other hand, the highest and lowest removal efficiencies were found as 15.17 and 2.85% for ciprofloxacin doses of 30 and 75 mg/L, respectively. Again, the greatest part of the removal efficiency was achieved through adsorption in the sludge (11.83%). This indicates that removal mechanisms for both pharmaceuticals were sludge adsorption as amoxicillin and ciprofloxacin biodegradations were low at all doses investigated. To compare experimental data with theoretical estimations, pharmaceutical removal was calculated in Sewage Treatment Plant (STP) using EPI Suite program. According to experimental results, the total removal efficiencies were consistent with theoretical estimations calculated by Environmental Protection Agency (EPA) Draft Method. There may be inconsistency between theoretical estimations and experimental results due to differences in experimental conditions caused by microbiological behaviors in the theoretical conditions. The removal efficiencies for amoxicillin and ciprofloxacin calculated by default method were lower than those calculated by EPA draft method since biodegradability is not taken into consideration in the default method.
      PubDate: 2022-04-01
       
  • Investigation on Sol-Gel Facilitated Synthesis of Silica Nanoparticles
           Using Kariba weed (KW-NS) and Its Efficiency in Cr(VI) Removal

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      Abstract: Environmental pollution is an aggressive change in the surroundings mainly because of heavy metals, dyes and organic pollutants, which are responsible for crucial natural and health issues. The undiscerning industrial activities make the water resources inappropriate for utilization and the accumulation of these pollutants in water is accountable for harmful effects on aquatic plants and animals. An eco-benign approach was explored for the synthesis of silica nanoparticles (KW-NS) using waste aquatic weeds. In the present study, waste aquatic Kariba weeds were utilized to synthesize and characterize silica nanoparticles and to investigate their applicability in the removal of Cr(VI) ions from aqueous as well as industry effluent. The silica nanoparticles using Kariba weeds (KW-NS) were prepared using sol-gel method and characterized using SEM, FTIR and BET analysis. Various parameters such as pH, adsorbent dosage, initial metal concentration and contact time on the adsorption of Cr(VI) were investigated and optimized. Adsorption isotherm, kinetics, thermodynamics, and regeneration mechanism were studied to determine the efficacy of KW-NS. The adsorption equilibrium for Cr(VI) was achieved at an optimum pH of 4.3 with 4 g L–1 adsorbent dosage at 60 min with 10 mg L–1 metal ion concentration and maximum adsorption capacity reached up to 96.54 mg g–1. The applicability of the synthesized KW-NS was checked with the tannery and electroplating industry effluent and posed 72 and 60% removal efficiency, respectively. Results obtained from this study indicate that the waste aquatic Kariba weed has the potential to synthesize silica nanoparticles in a more efficient and economical way than the conventional synthesis. These nanoparticles can be effectively applied as an adsorbent to treat industrial effluents for heavy metal removal.
      PubDate: 2022-04-01
       
  • Preparation of Electrochemically Activated Water in the Presence of
           Dispersed Fillers

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      Abstract: Since the quality of surface water has significantly deteriorated, consumers of tap drinking water are forced to additionally purify it by using various filters or low capacity reverse osmosis systems. Water purified by reverse osmosis barely contains mineral salts that are necessary for the human body. The electrochemical method is among the available options for correcting the composition of water, which makes it possible to obtain water with specified characteristics by controlling the conditions of the electrochemical process. Thus, this method allows one to obtain water with a negative redox potential (ROP) that brings antioxidant properties to water. A two-chamber electrochemical apparatus with the electrode compartments separated by a perforated cartridge filled with dispersed materials of different nature, such as cation exchange resin KU-2, activated granular carbon AG-3, and quartz sand, is used to purify tap water. It is shown that the energy consumption is <0.1 kW h/m3 when using a cation-exchange resin. In the time while the initial tap water flow is supplied to the anode chamber, from which it then passes through the cartridge into the cathode chamber and further into the water storage container, the ROP value of water decreases to –100 mV. In this case, water softens and the content of calcium ions decreases from 58 to 2–5 mg/L depending on the electrical current.
      PubDate: 2022-04-01
       
  • Cloud Point Extraction Coupled with Laser Thermal Lens Spectrometry for
           Determination of Trace Palladium in Environmental Water Samples

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      Abstract: A highly sensitive, simple and safe method has been developed for the determination of trace palladium by cloud point extraction (CPE) combined with thermal lens spectrometry (TLS). The method is based on the fact that formation of the stable hydrophobic complex of palladium(II) with a newly synthesized reagent 2-(5-iodo-2-pyridylazo)-5-dimethylaminoaniline (5-I-PADMA), and then extraction into the micellar phase of non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) as extracting agent at pH 4.8. Parameters that affect extraction efficiency, such as solution pH, concentration of 5-I-PADMA and Triton X-114, and equilibration temperature and time on CPE, were investigated and optimized. The results showed that an efficient extraction of palladium could be achieved with the following conditions were as follows: pH = 4.8 acetic acid-sodium acetate (HAc-NaAc) buffer solution, 100 μL 5 × 10–4 mol/L 5-I-PADMA, 800 μL 1.0% (w/v) Triton X-114, and heat-assisted at 60°C for 20 min. After phase separation, the surfactant-rich phase containing palladium complex was dissolved in 450 μL 2 mol/L HClO4-ethanol solution prior to its determination by TLS. A single mode He–Ne laser with 632.8 nm was employed for both excitation and probe beams. Under optimum experimental conditions, the calibration graph was linear over the range 0.1–7.5 ng/mL with a correlation coefficient of 0.9986. The detection limit was 1.0 ng/mL for palladium. The sensitivity enhanced by 558 times compared to that of the conventional spectrophotometry. The relative standard deviation (RSD) for elven replicate measurements of 1.0 ng/mL of palladium was 3.2%. The proposed method was applied to the determination of trace palladium in water samples.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010040
       
  • A Multivariate Statistical Approach to Pollution Source Identification in
           Cauvery River, South India

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      Abstract: This paper proposes the multivariate statistical methods, in particular, factor analysis and cluster analysis to assess and interpret the surface water quality of Cauvery River, South India. For this purpose, the surface water samples were obtained from the 50 monitoring stations along the 50 km river stretch during the periods of January 2018 and June 2018. In this approach, 23 parameters were used to measure the quality of collected water samples. The measured levels of turbidity, total dissolved solids, pH, ammonia and fecal coliforms exceed the Bureau of Indian Standards (BIS) for drinking water quality in 58, 35, 12, 11, and 30 samples, respectively. This shows that the surface water of Cauvery River is contaminated by pollutants from catchment area. The factor analysis infers that four principal components represent 71.78% of the total variance in the data set. Nutrient factor, organic factor, chemical factor, and mixed factor were identified as four principal components as per the factored loadings of variables. The agglomerative hierarchical grouping of 50 monitoring stations was carried out by cluster analysis, and these clusters were recognized subject to the spatial variation in surface water quality. Majority of locations (31 sites) fall under low pollution cluster and are influenced by runoff from catchment. The second cluster comprises 14 sampling sites influenced by domestic/urban sewage discharge and comes under moderately polluted category. The high pollution of third cluster is due to the industrial wastewater contamination in 5 monitoring stations. The study indicates that runoff contribution from catchment, urban sewage discharge, industrial wastewater discharge, and natural weathering processes are influencing the quality of Cauvery River water in the selected region. These primary sources are responsible for the abundant ionic concentrations and biological impurities in the Cauvery River. The legitimate treatment of urban and industrial wastewater and governance of anthropogenic activities in the Cauvery River catchment are essential for controlling the potential contamination of surface water.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010052
       
  • About the Mechanisms of Formation of the Chemical Composition of the
           High-Mountain Rivers of Central Asia: The Shakhdara River and its
           Contribution to the Hydrochemistry of the Transboundary Panj River

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      Abstract: Agriculture still predominates in the use of water resources in Central Asia. About 90% of the water resources generated in the region are used for irrigation. The quality of irrigation water is an important element in obtaining ecological and safe varieties of crops because, according to the data of IAEA, the transfer of radionuclides to the human body is carried out along a water–soil–plant–human body chain. Although such a chain explains the movement of radionuclides, it will also probably be implemented when pollutants enter the human body. The aim of this work is to determine the origin of the chemical composition of the Shakhdara River and its contribution to the enrichment of the main river Panj with chemical elements. Water sampling from the rivers Shakhdara and Panj is carried out in accordance with the guidelines of Sanitary Regulation “Sanitary and Epidemiological Requirements for Water Sources, Water ion Points for Economic and Potable Purposes, Economic and Potable Water Supply, Places of Recreational Water Uses and Safety of Waterbodies,” The elemental analysis is performed in the United States at the Laboratory of Ambient Environment and Geology of the Department of Geological Sciences of the University of Colorado (Boulder) as well as at the Laboratory of Moisture Chemistry of the Institute of Arctic and Alpine Studies. It is found upon comparing the results of chemical analyses with the criteria of various types of weathering (carbonate, silicate, evaporation of evaporites) that the formation of the chemical composition of the Shakhdara River occurs as a result of weathering of silicate rocks with the active participation of H2CO3 and H2SO4. It is established that the Shakhdara River makes a significant contribution to the enrichment of the Panj River with 3d (Fe, Co, Ni) elements as well as arsenic, vanadium, and scandium in addition to the alkaline (K, Na) and alkaline earth (Mg, Sr) elements.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010064
       
  • Influence of Natural Water Components on the Sorption of Dodecyl Sulfate
           Anions on Kaolinite

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      Abstract: To better understand the physicochemical processes occurring in natural reservoirs upon their contamination with the most common organic pollutants (anionic surfactants), the interaction of sodium dodecyl sulfate (DDSNa), sodium humate (HNa), and kaolinite from the Glukhiv deposit in distilled and natural artesian water is investigated. The influence of the natural water components on the states of the sorbent and sorbate is determined by a set of methods. The influence of Ca2+ ions and pH on the mechanism and value of adsorption of HNa on kaolinite is discussed. Increases in the adsorption capacity of the monolayer and the specific surface area of kaolinite are detected during the adsorption of humates from both distilled and artesian water. The influence of the formation of more surface-active than DDSNa but less soluble dodecyl sulfate salts with double-charged cations on the colloidal chemical properties of a solution of DDSNa in artesian water is demonstarted. Substantial leveling of the influence of mineral components on the surface activity and solubility of DDSNa upon the introduction of humates (natural polyelectrolytes) is established. The concentration ranges of the existence of different forms of the anionic surfactant (anions, insoluble salts, self-associates, intermolecular associates with humates, and micelles) in the studied systems and their influence on the sorption of the anionic surfactant on natural kaolinite are determined. It is shown that the isotherm of adsorption of anionic surfactants from artesian water is characterized by the presence of a maximum, which indicates a substantial effect of the precipitation of sparingly soluble salts of the dodecyl sulfate anion with doubly charged cations from artesian water. Moreover, the stepwise nature of the isotherm of adsorption of the anionic surfactant from artesian water in the presence of 5 mg/dm3 HNa may indicate the occurrence of multilayer adsorption, which is associated with following changes in the state of dodecyl sulfate upon changing its concentration in a solution: intermolecular associates with HNa and polyvalent ions with different DDSNa/HNa ratios in the surfactant associates and micelles. It is found that the addition of 5 mg/dm3 HNa to solutions of DDSNa in artesian water almost doubles the adsorption of DDSNa from its micellar solutions. It is established that low residual concentrations of DDSNa at the level of maximum permissible concentration (MPC) in water (DDSNa = 0.5 mg/dm3) ensure almost complete (R = 97%) removal of the humate from natural water, which is very important from the standpoint of environmental safety for understanding the influence of anionic surfactant pollutions on the state of aquatic ecosystems.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010027
       
  • Dairy Effluent Biodegradation by Endogenous Fungal Isolates in the
           Integrated Wastewater Treatment System

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      Abstract: The dairy industry is the fastest growing industry in the world. Discharged water is more easily contaminated with high levels of organic substances, pollutants and microbes. Consuming raw milk effluents can cause disease transmission to living beings and can be harmful to the environment. The present investigation was carried out for the characterization and its biodegradation process of dairy effluents using locally selected isolated fungi. For the biodegradation process, three species of fungi such as ASP, ALT, FUS were isolated and identified from dairy wastewater using the CFU method. During the monsoon, the dairy farm (CMP) collected the seasonal milk effluent. Aeration followed by filtration for degradation was performed. During the research some physicochemical parameters such as pH, BOD, COD, TDS, TSS, TKN, etc., were analyzed. Effluents from milk processing and ASP fungal isolate have been found to have a high capacity to break down organic matter. The BOD5 and COD value of the crude effluent improved by 87.75 and 81.02%, respectively, after 5 days. Biodegradation with fungal isolates can be a perfect method for treating dairy wastewater. This treatment technique can be used for industrial purposes, starting from selected fungal isolates, Aspergillus was more vital than Alternaria and Fusarium species for the biodegradation of organic content in dairy effluents. After studying all the aspects considered, aeration followed by filtration was extremely effective in reaching the most notable level of contamination present in wastewater. The possible reason could be related to the high adsorption capacity of activated carbon and assimilation by sawdust. Activated coal and sawdust can remove an assortment of organic matter from contaminated water. At long last, biodegradation of dairy wastewater by chosen fungal isolates is viable treatment technology, particularly on account of using locally isolated fungal strains.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010076
       
  • Determination of the Toxicity of Petroleum Products for Aquatic Organisms
           Using Comprehensive Bioassay

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      Abstract: We present the experimental results of the toxicity of the aquatic environment polluted with petroleum products (diesel fuel and AI-95 gasoline), obtained using complex bioassay of standard test organisms: daphnia Daphnia magna, freshwater hydra Hydra attenuate, and zebrafish Brachidanio rerio. Petroleum products have acute toxicity for all types of test organisms at a concentration of 0.1 cm3/dm3 for diesel fuel and 0.2 cm3/dm3 for AI-95 gasoline. The mechanisms of the toxic effect of petroleum products on hydrobionts are discussed. An ingress of a large amount of oil products into a natural reservoir threatens the functioning of the aquatic ecosystem due to a decline or disappearance of sensitive species of aquatic organisms, primarily invertebrates. Under these conditions, a film of insoluble fractions of oil products is formed on the water surface, the access of oxygen from the air to the water is disrupted (falls to 2–3 cm3 O2/dm3), and hydrobionts die from hypoxia. Water-soluble fractions of petroleum products enter organisms and poison them. The initial stages of development of aquatic organisms—fish embryos and fry or invertebrate nauplii—are the most sensitive to the toxic effects of petroleum products. Petroleum products caused an increase in the frequency of nuclear disorders in fish blood cells in surviving individuals, which indicates a genotoxic effect compared to the cytological parameters of the control group of fish.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010039
       
  • TiO2 Nanoparticles Effect on PVDF Membrane Filterability in Membrane
           Bioreactors: Fouling Reduction and Critical Flux Enhancement

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      Abstract: One of the important operational factors affecting the fouling of membrane bioreactors (MBR) is the critical flux which is defined as the flux above which the cake layer formation on the membrane surface is seen. So, to prevent severe fouling in MBR, it is important to determine the critical flux and operate at a flux below it. The evaluation of critical flux and pollutant removal in a lab-scale submerged membrane bioreactor was performed for a real oil refinery wastewater. Transmembrane pressure (TMP) and flux behavior in a period of time via a so-called flux step method were studied to determine the critical flux of the membrane and to investigate of the effect of TiO2 nanoparticles (NPs) incorporation into Polyvinylidene fluoride (PVDF) matrix, on the membrane filterability. The effectiveness of MBR for treating effluent stream of Dissolved Air Floatation (DAF) unit of Tehran oil refinery wastewater plant has been studied and the results showed that TiO2 NPs improved the phenol removal efficiency in such wastewater. About 70% enhancement in critical flux of PVDF/TiO2 membrane was observed as a result of TiO2 NPs tendency to reduce fouling of PVDF membranes. It was concluded that the effect of TiO2 incorporation in the membrane matrix is more significant in fouling reduction than permeability improvement and that the surface charge of the membrane plays much more important role than other surface modification strategies such as hydrophilicity enhancement, in fouling mitigation of MBRs. The results also demonstrated that TiO2 has no significant effect on the microorganism destruction or growth, since the amount of total soluble microbial products (SMP) and extracellular polymeric substance (EPS) remained almost stable during MBR operation for both membranes.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X2201009X
       
  • Determination of Zn, Mn, and Cd in Strata Water

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      Abstract: The effect produced by the Triton X-100 concentration and ultrasonic treatment time on the value of an analytical signal during the atomic absorption and inductively coupled plasma atomic emission determination of analytes in strata water was studied. When Triton X-100 was used, the sensitivity of atomic absorption analysis grew by 1.5 times for manganese, 1.6 times for zinc, and 1.8 times for cadmium. As a result of atomic absorption analysis with the use of a surfactant, atomization completeness was attained. Using the methods of atomic absorption and inductively coupled plasma atomic emission, the content of manganese, zinc, and cadmium in strata water was determined. The precision of analysis results was improved by using acetyl acetonates of metals, as the reference samples must be similar to the analyzed samples in their chemical composition. Using the standard addition method at a varied water sample volume, the systematic error was shown to be negligible at a relative standard deviation sr of less than 0.03. The consistency of results obtained by two independent methods was estimated by F- and t-criteria. The results were shown to have a uniform variance by the F-cirterion, and the average results could be summarized by the t-criterion. The developed method excluded the use of toxic and expensive reagents to be competitive by the atomic absorption detection limits: cmin for Cd, Mn, and Zn was found to be 0.002 µg/mL.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010118
       
  • A Two-Stage Batch System for Phosphate Removal from Wastewater by
           Iron-Coated Waste Mussel Shell to Assess the Optimum Adsorbent Dosage

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      Abstract: High amounts of phosphate discharged in receiving water can lead to eutrophication. Once a water body is enriched with phosphate, it can prompt the growth of plants and cause algal blooms. The water body may also lose its important functions and cause adverse effects on the environment and human health. In this study, removal of phosphate from domestic wastewater treatment plant effluent was elucidated using iron-coated waste mussel shell. The phosphate adsorption by iron-coated waste mussel shell was examined with respect to initial phosphateconcentration (7 mg L–1), solution volume (0.2 L), adsorbent dosage (4–20 g), and contact time (1–5 day). The chemical composition of iron-coated waste mussel shell was analyzed using energy dispersive X-ray fluorescence spectrometer. The measurement of the specific surface area of iron-coated waste mussel shell was performed by multiple-point method according to the Brunauer, Emmett, and Teller theory. Several kinetic models (i.e., pseudo-first order and pseudo-second order) and isotherm models (i.e., Freundlich and Langmuir) were used to describe the adsorption behavior. The optimum removal efficiency of phosphate can reach at 95.7% after 120 h with the amount of iron-coated waste mussel shell used to run the experiment was 20 g and the treated effluent phosphate concentration of 0.3 mg L–1, was verified. Experimental data can be well described by pseudo-second order kinetic model (R2 > 0.99) and Freundlich isotherm model (R2 = 0.93), suggesting that chemisorption and multilayer adsorption occurred. Furthermore, a two-stage batch system was proposed to assess the optimum adsorbent dosage for phosphate removal. The two-stage system has contributed to reduce iron-coated waste mussel shell dosage by 56.94%, as compared to one-stage and thus reduced the operating cost of iron-coated waste mussel shell.
      PubDate: 2022-02-01
      DOI: 10.3103/S1063455X22010088
       
  • Potential Risks Assessment of Trihalomethanes in Drinking Water Supply

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      Abstract: Chlorine is widely used in the disinfection process of water supply systems to eliminate pathogens. However, a complication that occurs during the disinfection process is the formation of by-products that include volatile organic compounds such as chloroform and other trihalomethanes. This study is intended to assess the risk of trihalomethanes in tap water. Water samples were taken from end-user tap water near wastewater treatment plants in various locations in Perlis, Malaysia. Following the standard procedure and calculation method proposed by the US EPA, the exposure dose (mg/kg day)) for oral ingestion, dermal absorption and inhalation was calculated. A total of 90 independent data were obtained from the Perlis regions. Risk assessments were calculated and three groups were formed to represent three separate waste water treatment plants. The assessment of cancer risk in the Timah Tasoh area by ingestion routes for dibromochloromethane, bromo-dichloromethane and chloroform was 3.04 × 10–5, 1.73 × 10–4, and 2.67 × 10–5, while for the dermal pathway it was 6.65 × 10–4, 3.97 × 10–4, and 7.19 × 10–5 and inhalation for dibromochloromethane, bromodichloromethane, bromoform and chloroform—1.33 × 10–3, 1.02 × 10–3, 1.38 × 10–3, and 6.32 × 10–5. Another study area, Kuala Sungai Baru, has the lowest trihalomethane content. Obviously, the lowest risk as some of the compounds were found to be below the US EPA limit. The combined risk of cancer in these three study areas for the ingestion method was 1.23 × 10–5, 1.07 × 10–4, and 1.11 × 10–5. The results showed that the carcinogenic risk assessed for chloroform, bromodichloromethane and dibromochloromethane was within the established limit in some areas, but exceeded the acceptable level in other areas of the study. In addition, the greatest risk from trihalomethanes appears to arise from inhalation followed by ingestion and skin contact. This study made the Perlis Exploration Area Warning as a reference point for other nearby areas.
      PubDate: 2021-11-01
      DOI: 10.3103/S1063455X21060060
       
 
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